Wireless-telegraph transmitter.



G. P. STEINMETZ. WIRELESS TELEGRAPH TRANSMITTER. APPLICATION FILEDAPR.20,1907.

91 0,430. Patented Jan. 19, 1909.

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UNITED STATES Pn'rENr orrrcni CHARLES P. STEINMETZ, OF SCHENEGTADY, NEWYORK, ASSIGNOH TO GENERAL ELECTRIQ GOMPA'N'Y, A CORPORATION OF NEW YORK.

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To all whom it may concern:

Be it known that I, CHARLES P. STEIN- METZ, a citizenof the UnitedStates, residing at Schenectady, county of Schenectady, State of NewYork, have invented certain new and useful Improvements in Wireless-Telegraph Transmitters, of which the following is a specification.

My invention has reference to improvements in space telegraphy, and itsobject is the substitution of the 'use of uni-directional current ofhigh potential in lace of alternating currents heretofore-use forcharging the condenser which discharges through an air or 'spark gap,and thus produces varia-- tions of potential in an elevated conductor orantenna, hlQh then, emits e ectromagnetic I waves which propagatethrQIlgh h air-and arev absorbed at a i tant antenna, and are.

tained constant with the em loyment of al ernati currents of such highpotential and volume as are required for. long distance space;telegraphy. By my invention this diiiic-ulty is overcome since inaccordance therewith a uni-directional current, of any desired'voltageis\produced in the charging circuit b a primary source of alternatingcurrent of any potential, and preferably of moderate potential.

The accompanying drawing illustrates in diagram an apparatus organizedin accordance withmy invention.

In this drawing 1, 2, represent a transmission line of alternatingcurrents of moderate potential from which two branches 3, 4, and 5', 6,are derived, the former containing a reactance coil 7 and the latter areactance coil 8 for limiting the amount of current derived from themain line. The branch circuit 3, l, contains the primary coil 9 of' astep-up transformer 10, the secondary, 11, ofwhich is connected with amercury arc Specification of Letters Patent.

Application filed April 20, 1907, Se ial No, 369,3 2.

Patented Jan. '19, 1969.

- rectifier 12 in the manner hereinafter described. The branch circuit'5, 6, also con-. tainsa primary 13 of a step-up transformer 1%, thesecondary coil, 15, of which is' alsoconnected with the mercury arcrectifier.

g The mercury arc rectifier 12 is constructed as" usual of glass and is,in efi'ect,'a branched vessel, into the two main branches 16, 17, ofwhich, the terminals 18, 19 of the secondary coil of the transformer10-are sealed. Below the two main branches 16, 17, of the rectifier, arethe three subsidiary branches 20, 21,22, which are filled with mercuryas indicated, and into each of them projects and is sealed a wire; whichis immersed in the 'mercury in these subsidiary branch tubes or ockets,

hewire proj cting into the centre pocket 21. is connected out ide ofthereetifier. with ne armature of. the. condenser 23 y a com octor 24,and a rea taneeeoil. 25. isineluded' in this conductor for a purposewhich Will presently appear, This same armature of the condenser is alsoconnected to ground at 26, while with the other armature is con.-vnected a r actance coil or auto-transformer 2 p e r 1y ithout an iron cre, and with the elevated conductor or antenna 28j. The. auto-transformeis adjustablytapped at an appropria e predetermined. po nt by conductor29 hich exten s o an is c m ne ted with. he c ntra par of th seeondar,winding of thetran foi pmer l The. spar... 'aep device. 30 is in crcuit s un ing theoo denser and a portion of the au o r nsf rmer betweenthe c nd ct rs 2% an 29-. In the circuit 3, 4 is included a telegraphkey 31 byswhich t at circuit may be opened and closed 'n accordance witha telegraphers code, in the usual manner.

The operation of the apparatus so far de scribed is as, follows :-Whenthe key 31 is depressed to closethe circuit 3, 4, alternating currentsof an amount largely deter mined by the reactance coil 7, pass throughthe primary 9 of the step-up transformer 10, and the secondary currentsof high potential, discharging from the secondary coil of thattransformer, give uni directional impulses in the circuit which includesthe condenser.

Considering the impulse discharging from the left hand end of thesecondary of the transformer, it proceeds to its terminal 18, sealed inthe branch 16 of the rectifier and to the mercury in the middlepocket21, and

by conductor 24, reaction coil earns condenser, a portion of theauto-transformer, and conductor 29, back to the central point of thesecondary coil of the transformer 10.

The following impulse from the secondary coil, proceeding from the righthand end of 5 the same, reaches the terminal 19. sealed in i the arm 17of the rectifier, and through the coil 15.

What I claim as new and desire to secure I by Letters Patent of theUnited States, is,

mercury vapors in the same to the mercury in the central pocket 21, andby conductor 3' 24, reaction coil 25, condenser, auto-transformerconductor 29, again back to the cenj tral portion of the secondary oftransformer 10. Thus, the impulses which pass through the condenser areuni-directional, and they are renderedpractically uniform by the currentleveling reaction coil 25, which may be located in any portion of eitherthe conductor 24 or the conductor 29. The capacity of the condenser andthe inductance of that portion of the auto-transformer which is includedin the discharging circuit, are so proportione'd that the discharges ofthe condenser through the air gap at 30 will occur with the desiredfrequency.

In order that all of the'impulses from the secondary of the transformer10 may surely pass through. the rectifier, it is necessary that the samebe primed, and such priming is secured by the impulses delivered to therectifier by the transformer '14. In the primary circuit of thistransformer is a switch by which that circuit is closed. an instantbefore signals are transmitted by ,the operation of the key 31. Thetransformer 14 would ordinarily be a step-up transformer, but the rateof its transformationnmy be considerably'lower than that of thetransformer 10. The upper end of the secondary of transformer 14 isconnected with the mercury cup 20 by the con' lductor 33; the middleportion of that secondary is connected by conductor 34 with theconductor 24 which terminates in the mercury cup 21, and the lowerterminal of the secondary of transformer 1 1 is connected by conductor35 with the mercury cup 22. Preferably, but not necessarily, a reactioncoil 25 is included in the conductor 34, and it serves the same purposeas reaction coil 25, namely, to render the impulses delivered to therectifier by the transformer 14 practically continuous and uniform. Theoperation of this priming device is well understood in the art, and itis barely necessary to say that any impulse starting from the upperterminal of the secondary coil 15 proceeds by conductor 33,

mercury cup 20, through the small space between thiscup and cup 21, andby conductor 34 back to the central portion of the secondary coil 15.Any impulse starting from the lower terminal of the secondary coil 15proceeds by conductor 35 to mercury cup 22, and through the short spacebetween this cup and cup 21, and returns by conductor 34 to the middleportion of the secondary 1. A space-telegrapl'i transmitter containmg asparking gap fed by a condenser, in combination with a source ofalternating current, means for converting the alternatmg impulses intohigh tension un -dn'ectional current of substantially uniform strength,and means for charging the con: denser by the converted current,substantially as described.

2. A space-telegrapl'i transmitter containing a sparking gap fed by acondenser, in combination with a source of alternating currents, atransformer and mercury arc rectifier for converting the alternatingimpulses into high tension uni-directionalimpulses, and circuitconnections for charging the condenser with the rectified current,substantially as described.

. 3. In a space-telegraph transmitting equipment, the combination of asparking gap fed by periodic discharges of a condenser, a transmissionline carrying alternating currents of con'lparatively low potential, astepup transformer charged from the line, a

mercury arc rectifier receiving the discharges from the transformer anddischarging into the condenser, and means for leveling the rectifierdischarges, substantially as described.

4. In aspace-telegraph equipment, .the combination of a sparking gap fedby periodic discharges of a condenser, a transmission line carryingalternating currents of comparatively low potential, a step-uptransformer charged from the line, a mercury arc rectifierreceiving't'he discharges from the transformer and discharging into thecondenser, means for leveling the rectifier discharges, an antennae anda ground connection, and a transmitting key in thelow potential circuit,substantially as described.

In'witness whereof, I have hereunto set my hand this 19th day of April,1907.

CHARLES P. STEIN METZ.

